Liquid crystal display device, substrate assembly for liquid crystal display device, and electronic apparatus having a substantially equivalent display quality in both transmissive and reflective display modes

ABSTRACT

A transflective liquid crystal display device comprising a pair of substrates; a liquid crystal layer between the substrates; reflective films are provided on an internal surface of a lower substrate which reflects light incident from an upper substrate; color filters provided above the reflective films, each containing a plurality of color layers which have different colors and are disposed to correspond to dots forming a display region; and lighting means. The dots have a reflective region in which the reflective film is present and a transmissive region in which the reflective film is not present. In addition, the color filters have opening portions that overlap the reflective film in each dot. Since the non-color regions are provided in the color filter corresponding to the reflective films, light used in reflective display mode is sufficiently secured and the chroma in a transmissive display mode can be maintained.

TECHNICAL FIELD

The present invention relates to liquid crystal display devices,substrate assemblies used for liquid crystal display devices, andelectronic apparatuses, and more particularly, relates to atransflective liquid crystal display device having superior visibility,in which sufficiently bright display can be performed not only in atransmissive display mode but also in a reflective display mode.

BACKGROUND ART

Since electrical power consumption has been small since light sourcessuch as a backlight are not provided, reflective liquid crystal displaydevices have been widely used for various portable electronicapparatuses. However, in reflective liquid crystal display devices,since display is performed using outside light such as natural light orillumination light, there has been a problem in that it has beendifficult to view the display in a dark place. Accordingly, a liquidcrystal display device has been proposed in which display can be viewedin a bright place by using outside light, as is a general reflectiveliquid crystal display device, and can also be viewed in a dark place byusing a built-in light source such as a backlight. That is, in theliquid crystal display device described above, a reflective and atransmissive display mode are both provided, and in accordance withambient brightness, the reflective or transmissive display mode can beselectively used. As a result, while decreasing electrical powerconsumption, clear display can be performed when it is dark.Hereinafter, in this specification, this type of liquid crystal displaydevice is called “transflective liquid crystal display device”.

In recent years, concomitant with advancement of portable electronicapparatuses, OA apparatuses, and the like, apparatuses having colorliquid crystal displays have been requested. In addition, in the fieldof the transflective liquid crystal display apparatuses described above,color displays have been increasingly desired. As a transflective liquidcrystal display device that can respond to the request described above,the structure in which a color filter is provided on one of an uppersubstrate and a lower substrate has been proposed. In the case of thethis type of transflective color liquid crystal display device, in areflective display mode, after passing through the color filter, outsidelight incident from the upper substrata side is reflected from areflective layer and then passes again through the color filter. On theother hand, in a transmissive display mode, illumination light incidentfrom the lower substrate side by lighting means such as a backlightpasses through the color filter. In the general structure, in both areflective display mode and a transmissive display mode, display hasbeen performed using the same color filter.

In this type of transflective liquid crystal display device, asdescribed above, incident light passes through the color filer twice ina reflective display mode and once in a transmissive display mode,thereby performing color display. Accordingly, for example, in the casein which the color filter having pale tints is used so as topreferentially display colors in a reflective display mode in whichlight passes twice through the color filter, it is difficult to obtainfine color display in a transmissive display mode in which incidentlight passes through the color filter only once. However, in order tosolve the problem described above, in the case in which a color filterhaving dark tints are used so as to preferentially display colors in atransmissive display mode in which light passes once through the colorfilter, display in a reflective display mode in which incident lightpasses twice through the color filter becomes dark, and as a result,sufficient visibility cannot be obtained. As described above, inconventional transflective liquid crystal display devices, it has beendifficult to perform display exhibiting fine colors and having highvisibility in both a reflective display mode and a transmissive displaymode.

The present invention was made in order to solve the problems describedabove, and an object of the present invention is to provide atransflective liquid crystal display device in which display exhibitingfine colors and having superior visibility can be performed in both areflective and a transmissive display mode. In addition, the presentinvention has an object to provide a substrate assembly for forming theliquid crystal display device described above and to provide anelectronic apparatus comprising the liquid crystal display device thathas superior visibility.

DISCLOSURE OF INVENTION

In accordance with a first aspect of the present invention, atransflective liquid crystal display device comprises a pair ofsubstrates which are an upper substrate and a lower substrate and whichfaces each other; a liquid crystal layer provided between the pair ofsubstrates; reflective films which are provided on the internal surfaceof the lower substrate and which reflect light incident from the uppersubstrate; color filters provided above the reflective films, eachcontaining a plurality of color layers which have different colors andwhich are disposed so as to correspond to dots forming a display region;and lighting means provided at the outer surface of the lower substrate,each of the dots having a reflective region in which the reflective filmis present and a transmissive region in which the reflective film is notpresent for performing transflective display,

wherein each of the color filters has non-color regions in regions eachoverlapping, in plan view, the reflective film in each dot.

According to this liquid crystal display device, since the non-colorregions are provided in the color filter corresponding to the reflectivefilms, the amount of light used in a reflective display mode can besufficiently secured, and the chroma in a transmissive display mode canalso be maintained. For example, even when the transmittance of thecolor filter is decreased so that the chroma in a transmissive displaymode is improved, since a part of light reflected from the reflectivefilm is allowed to pass through the non-color region of the colorfilter, decrease in amount of light can be suppressed, and hence thebrightness in a reflective display mode can be maintained. In thisliquid crystal display device, opening portions are preferably formed inthe color filter so as to be used as the non-color regions. Thestructure may be formed in which the color filters are provided for theupper substrate. In addition, of course, the color filters may also beprovided for the lower substrate.

As described above, in the liquid crystal display device having thestructure described above, since a part of light incident from the uppersubstrate side passes through the non-color region in a reflectivedisplay mode, in a reflective display mode, light after passing throughthe color filter twice comprises non-colored light passing through thenon-color region and colored light passing through a region (hereinafterreferred to as “color region”) in which the color layer is present. Onthe other hand, in a transmissive display mode, all the light that isemitted from the lighting means and passes through the transmissiveregion passes through the color region, and hence all the light passingthrough the color filter once in a transmissive display mode is coloredlight. As described above, since the difference in tint of color betweenlight passing through the color filter twice in a reflective displaymode and light passing through the color filter once in a transmissivedisplay mode can be reduced, when the color layers of the color filterare optimized, display exhibiting fine colors in both a reflective and atransmissive display mode and having superior visibility can beobtained. That is, since the reflective region and the transmissiveregion are provided in each dot (that is, in each subpixel), and thenon-color region is provided in the reflective region, by the behaviorof incident light as described above, display exhibiting fine colors inboth a reflective and a transmissive display mode and having superiorvisibility can be obtained.

When a liquid crystal display device having the structure describedabove is realized using a general method, in a manufacturing process,problems may arise in some cases in that variation in area of thenon-color region becomes large, or misalignment occurs between thereflective region and the no-color region. As a result, irregularitiesin image or color displayed on a screen of one liquid crystal displaydevice, variation in display properties between liquid crystal displaydevices, or the like may be generated thereby.

Accordingly, in accordance with a second aspect of the presentinvention, a transflective liquid crystal display device comprises apair of substrates which are an upper substrate and a lower substrateand which face each other; a liquid crystal layer provided between thepair of substrates; reflective films which are provided on the internalsurface of the lower substrate and which reflect light incident from theupper substrate; color filters provided above the reflective films, eachcontaining a plurality of color layers which have different colors andwhich are disposed so as to correspond to dots forming a display region;and lighting means provided at the outer surface side of the lowersubstrate, each of the dots having a reflective region in which thereflective film is present and a transmissive region in which thereflective film is not present for performing transflective display. Inthe liquid crystal display device described above, the reflective filmsare formed in a strip shape extending along dot rows or dot linescomposed of the dots disposed in one direction, the reflective filmshave width expansion portions in the respective dots, and non-colorregions in which the color layers of each color filter are not presentare each provided in at least a part of a region overlapping, in planview, each width expansion portion of the reflective film in thecorresponding dot.

In order to solve the problems of the liquid crystal display deviceaccording to the first aspect of the present invention, in the liquidcrystal display device according to the second aspect, the reflectivefilm having a particular shape is specified, and the position of thenon-color region provided with respect to the corresponding reflectivefilm is specified. That is, the features of the second aspect of thepresent invention are that the reflective films are formed in a stripshape extending along the rows or the lines composed of the dotsdisposed in one direction and have width expansion portions, having alarger width than that of the other part, in the respective dots, andthat the non-color region is disposed in the region overlapping, in planview, the width expansion portion in the corresponding dot.

According to this structure, variation in area of the non-color regionor misalignment between the reflective region and the no-color region inmanufacturing process can be reduced, and as a result, variation indisplay properties can be suppressed. The reasons why the problems inthat variation in area of the non-color region or misalignment betweenthe reflective region and the no-color region are likely to occur in thestructure of the liquid crystal display device according to the firstaspect and the reasons why the problems described above can be solved inthe structure of the liquid crystal display device according to thesecond aspect will be described in detail in “Description of PreferredEmbodiments” with reference to drawings.

In addition, the liquid crystal display device according to the secondaspect may further comprise transparent conductive films each disposedin the reflective region and the transmissive region so as to cover atleast the upper surface of each of the reflective films, wherein theselaminated films each composed of the transparent conductive film and thereflective film may be formed into strip-shaped electrodes extending inthe dot rows or the dot lines.

In this structure, since the transparent conductive film and thereflective film cooperatively form the strip-shaped electrode, due tothe presence of the transparent conductive film located in thetransmissive region, application of an electric field to the liquidcrystal layer above the transmissive region can be smoothly performed,and in addition, due to the presence of the reflective film composed ofa metal having a small resistivity as compared to that of thetransparent conductive film, an effect in that the resistance of theentire electrode is reduced can be obtained. As described above, thestrip-shaped electrodes can be formed for a passive matrix type liquidcrystal display device or an active matrix type liquid crystal displaydevice using thin-film diodes (hereinafter referred to as TFDs) as aswitching element.

In addition, in the liquid crystal display device of the presentinvention, among the dots corresponding to different colors, each of thedots corresponding to at least one of the colors may have the non-colorregion having an area different from that of the non-color region ofeach of the dots corresponding to the other colors.

According to this structure, since the reflectance and the chroma ofeach color light can be adjusted for the individual dots correspondingto the color different from the others, the reflectance and the chroma(for example, hue in white display) of the entire reflected light can beoptionally adjusted, and hence display quality such as displaybrightness and color in a reflective display mode can be improved.

In more particular, when the plurality of color layers having differentcolors are composed of red layers, green layers, and blue layers, thearea of the non-color region of each of the dots corresponding to thegreen layers is preferably set to larger than the area of the non-colorregions of each of the dots corresponding to the red layers and the bluelayers.

Green color has a significantly high spectral luminous factor for thehuman eyes as compared to that of each of red and blue color.Accordingly, when the area of the non-color region in the dot for greencolor is set to large as compared to that of the non-color region ineach of the dots for red color and blue color, as the overall reflectivelight, the reflectance and the color reproducibility can be improved.

In addition to the structure described above, among the dotscorresponding to different colors, each of the dots corresponding to atleast one of the colors may have the transmissive region having an areadifferent from that of the transmissive region of each of the dotscorresponding to the other colors.

According to the structure described above, since the transmittance andthe chroma of each color can be adjusted for individual dotscorresponding to different colors, the transmittance and the chroma (forexample, hue in white display) of the entire transmitted light can beoptionally adjusted. As a result, when this adjustment is performedtogether with that of the areas of the non-color regions describedabove, optical properties such as reflectance, transmittance, chroma ofreflected light, chroma of transmitted light, and the like can berespectively adjusted, and hence display quality in both a reflectivedisplay mode and a transmissive display mode can be equally optimized.

In more particular, when the plurality of color layers having differentcolors are composed of red layers, green layers, and blue layers, thearea of the transmissive region in each of the dots corresponding to thegreen layers is preferably set to smaller than the area of thetransmissive regions of each of the dots corresponding to the red layersand the blue layers.

As described above, since green color has a high spectral luminousfactor as compared to that of each of red color and blue color, when thearea of the transmissive region of the dot corresponding to green coloris set to smaller than that of the transmissive region of each of redand blue colors, the color balance is not degraded, and in addition, asufficient transmittance can be maintained.

In addition, in the dot described above, it is preferable that thereflective region and the transmissive region in each of the dots bedisposed adjacent to at least one side of a plurality of sides definingthe each of the dots and be disposed adjacent to each other along saidat least one side. In this case, as the at least one side of the dot, apair of sides opposing each other among the plurality of sides definingthe dot in an approximately rectangular shape may be considered.According to this structure, due to errors in manufacturing, even when apart of the dot in the vicinity of the periphery thereof becomes unableto perform display, since the areas of the reflective region and thetransmissive region are both decreased, decrease in area of only one ofthe regions described above can be avoided. Accordingly, even whenmanufacturing errors occur, the case in which the areal ratio of thereflective region to the transmissive region is changed from apredetermined areal ratio can be avoided, and as a result, the balanceof display quality between a reflective display mode and a transmissivedisplay mode can be maintained. For example, in a liquid crystal displaydevice having a shading layer shading the peripheries of dots, due tomanufacturing errors, the shading layer may overlap a part of the dot inthe vicinity of the periphery thereof, and hence this part of the dotmay become unable to perform display in some cases. Even in this case,according to the present invention, change in areal ratio of thereflective region to the transmissive region from a predetermined(designed) areal ratio can be suppressed.

In addition, on the lower substrate described above, it is preferablethat electrodes be provided for applying a voltage to the liquid crystaldescribed above and that the reflective films have electricalconductivity and be electrically connected to the electrodes describedabove. According to this structure, compared to the case in which theelectrodes are independently (separately from the reflective films)provided, the resistance can be reduced.

Next, in order to solve the problems described above, anothertransflective liquid crystal display device of the present inventioncomprises a pair of substrates which are an upper substrate and a lowersubstrate and which face each other; a liquid crystal layer providedbetween the pair of substrates; reflective films which are provided onthe internal surface of the lower substrate and which reflect lightincident from the upper substrate; color filters provided on theinternal surface of the upper substrate, each containing a plurality ofcolor layers which have different colors and which are disposed so as tocorrespond to dots forming a display region; and lighting means providedat the outer surface side of the lower substrate, each of the dotshaving a reflective region in which the reflective film is present and atransmissive region in which the reflective film is not present forperforming transflective display. In the liquid crystal display devicedescribed above, the color filters each have non-color regions in whichthe color layers are not present, each non-color region being providedin at least a part of region overlapping, in plan view, the reflectiveregion in each dot, and the distance between the end of the reflectiveregion and the end of the non-color region, which oppose each other, isset to more than 15 μm.

According to this structure, since the end of the reflective film andthe end of the non-color region, which oppose each other, is set to morethan 15 μm, the non-color region does not protrude outside toward thetransmissive region side, and hence the case in which desired opticalproperties are not obtained can be avoided. In addition, since alignmentallowance is increased, the structure having resistance against bondingmisalignment can be formed, and in addition, desired optical propertiescan be easily obtained. The detail will be described in “Description ofPreferred Embodiments”.

In addition, the present invention may be applied to a substrateassembly for use in a liquid crystal display device. That is, thesubstrate assembly may be provided with reflective films and disposed atthe rear side of a liquid crystal display device or may be provided atthe observer side of a liquid crystal display device without havingreflective films.

That is, the former substrate assembly is used for a liquid crystaldisplay device comprising dots corresponding to different colors, andcolor filters which are provided to overlap the dots, which transmitlight having wavelengths corresponding to the colors for the dots. Theformer substrate assembly comprises a first substrate of a pair ofsubstrates opposing to each other, for holding liquid crystal with asecond substrate; and reflective films which are provided on the firstsubstrate, which overlap a part of the respective dots, entireperipherical edges of which are disposed in the dots and which reflectlight incident from a second substrate of the pair of substrates,wherein the shape of each of the reflective films is selected so thatthe opening portions are each disposed in a region overlapping each ofthe reflective films in the respective dots. In this substrate assembly,the color filters described above may be provided on the firstsubstrate.

In addition, the latter substrate assembly is used for a liquid crystaldisplay device comprising a pair of substrates opposing to each otherfor holding liquid crystal therebetween, and dots corresponding todifferent colors. The latter substrate assembly comprises a firstsubstrate of a pair of substrates opposing to each other for holding theliquid crystal with a second substrate provided with reflective filmswhich overlap a part of the dots, entire peripheral edges of which aredisposed in the dots and which reflect light; and color filters whichare provided on the first substrate so as to overlap the dots and whichtransmit light having wavelengths corresponding to the colors for thedots, the color filters being provided with opening portions inrespective region each overlapping one of the reflective films disposedin the respective dots.

Next, an electronic apparatus of the present invention comprises theliquid crystal display device described above. According to thisstructure, an electronic apparatus comprising a liquid crystal displaydevice, which can exhibit fine colors in both a reflective display modeand in a transmissive display mode and has superior visibility, can beprovided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view showing the structure of a liquidcrystal panel according to a first embodiment of a liquid crystaldisplay device of the present invention.

FIG. 2 is a plan view showing the relationship among common electrodes,segment electrodes, and reflective layers of the liquid crystal panelshown in FIG. 1.

FIG. 3 is a graph showing transmittance properties of color filters ofthe liquid crystal panel shown in FIG. 1.

FIG. 4 is a cross-sectional view showing the relationship between thesegment electrode and the reflective layer of the liquid crystal panelshown in FIG. 1.

FIG. 5 includes a plan view and a cross-sectional view showing thepositional relationship among dots, the color filters, and thereflective layers of the liquid crystal panel shown in FIG. 1.

FIG. 6 includes views showing examples for illustrating en effect of thefirst embodiment for the sake of comparison.

FIG. 7 includes views for illustrating effects of the first embodiment.

FIG. 8 is a cross-sectional view showing the structure of a liquidcrystal panel according to a second embodiment of a liquid crystaldisplay device of the present invention.

FIG. 9 includes a plan view and a cross-sectional view showing thepositional relationship between dots, color filters, and reflectivelayers of the liquid crystal panel shown in FIG. 8.

FIG. 10 is a cross-sectional view showing the structure of a liquidcrystal panel according to a modified embodiment of the presentinvention.

FIG. 11 is a cross-sectional view showing a schematic structureaccording to a third embodiment of a liquid crystal display device ofthe present invention.

FIG. 12 is an enlarged plan view showing a plurality of pixels forming adisplay region of the liquid crystal display device shown in FIG. 11.

FIG. 13 is an enlarged plan view showing a plurality of pixels forming adisplay region according to a fourth embodiment of a liquid crystaldisplay device of the present invention.

FIG. 14 is a plan view showing another example of an expansion portionof a reflective film of a liquid crystal display device according to thepresent invention.

FIG. 15 is a plan view showing still another example of the expansionportion of a reflective film of a liquid crystal display deviceaccording to the present invention.

FIG. 16 is a view showing a planar pattern in which areas of individualelements of structural example 1 of an embodiment according to thepresent invention are realized in a conventional structure.

FIG. 17 is a view showing a planar pattern in which the areas of theindividual elements of structural example 1 of the embodiment accordingto the present invention are realized in the structure of the presentinvention.

FIG. 18 is a view showing a planar pattern in which areas of individualelements of structural example 2 of an embodiment according to thepresent invention are realized in the structure of the presentinvention.

FIG. 19 is a view showing a planar pattern in which areas of individualelements of structural example 3 of the embodiment according to thepresent invention are realized in a conventional structure.

FIG. 20 is a view showing a planar pattern in which the areas of theindividual elements of structural example 3 of the embodiment accordingto the present invention are realized in the structure of the presentinvention.

FIG. 21 is a graph showing the spectral properties of color filters usedin structural example 2 of the embodiment of the present invention.

FIG. 22 is a graph showing the spectral properties of color filters usedin structural example 3 of the embodiment of the present invention.

FIG. 23 is an enlarged plan view showing a plurality of pixels forming adisplay region of a liquid crystal display device, which is alreadyfiled by the inventors of the present invention.

FIG. 24 is a perspective view showing the structure of a personalcomputer as an example of an electronic apparatus to which a liquidcrystal display device of the present invention is applied.

FIG. 25 is a perspective view showing the structure of a mobile phone asan example of an electronic apparatus to which a liquid crystal displaydevice of the present invention is applied.

DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described withreference to drawings. In the embodiments described below, thestructures of the present invention are disclosed, but are not intendedto limit the present invention. In addition, any modification may beperformed without departing from the scope and sprit of the presentinvention. In the figures shown below, in order to facilitateunderstanding of individual layers and constituent members, thereduction scales thereof are made different from each other.

First Embodiment

First, referring to FIG. 1, an embodiment in which the present inventionis applied to a passive matrix type transflective liquid crystal panelwill be described. As shown in the figure, a liquid crystal displaydevice comprises a liquid crystal panel 1 and a backlight unit 4. Theliquid crystal panel 1 has the structure in which a first substrate(upper substrate) 10 and a second substrate (lower substrate) 20opposing thereto are bonded to each other with a sealing material 30provided therebetween, and liquid crystal 31 such as a TN (twistednematic) or a STN (super twisted nematic) type is enclosed in a regionsurrounded by the two substrates described above and the sealingmaterial 30. The backlight unit 4 is disposed at the second substrate 20side of the liquid crystal panel 1. Hereinafter, as shown in FIG. 1, aside opposite to the backlight unit 4 with respect to the liquid crystalpanel 4 is called “observation side”. That is, the “observation side”means a side at which an observer viewing a display image on the liquidcrystal panel 1 is present.

The backlight unit 4 contains a light source 41 and light guide pale 42.The light source 41 is formed, for example, of an LED (Light EmittingDiode) or a cold cathode tube and irradiates a side-end surface of thelight guide plate 42 with light. The light guide plate 42 is a platemember to guide light incident on the side-end surface, emitted from thelight source 41, uniformly to a substrate surface of the liquid crystalpanel 1. In addition, a diffuser is adhered to the surface of the lightguide 42 opposing the liquid crystal panel 1 for uniformly diffusinglight incident from the light guide 42 to the liquid crystal panel 1,and onto the surface of the light guide 42 at the side opposite to thatdescribed above, a reflective layer is adhered for reflecting light tothe liquid crystal panel 1 side, which light is incident from the lightguide plate 42 to the side opposite to the liquid crystal panel 1 (bothof then are not shown in the figure). In this structure, the lightsource 41 is not always turned on, and when the liquid crystal displaydevice is used in a place at which outside light is not sufficient, thelight source 41 is turned on in accordance with the instruction by auser or a detection signal from a sensor.

In addition, the first substrate 10 and the second substrate 20 of theliquid crystal panel 1 are plate members, for example, formed of asglass, quartz, or plastic, having light transmission properties. Ontothe outside (side opposite to the liquid crystal 31) surface of thefirst substrate 10, a retardation film 101 which compensates forinterference color and a polarizer 102 polarizing incident light areadhered. In a manner similar to that described above, a retardation film201 and a polarizer 202 are adhered onto the outside (side opposite tothe liquid crystal 31) surface of the second substrate 20.

On the first substrate 10, a plurality of common electrodes 14 isprovided. In this embodiment, FIG. 2 is a plan view of showing thestructure of some elements forming the liquid crystal panel 1. Across-sectional view taken along the line A-A′ in FIG. 2 corresponds tothe view shown in FIG. 1. As shown in FIGS. 1 and 2, each commonelectrode 14 is a strip-shaped electrode formed of a transparentconductive material such as ITO (Indium Tin Oxide), and extends in the Xdirection shown in the figure.

In addition, on the second substrate 20, a plurality of segmentelectrodes 22 is provided. As is the common electrode 14, each segmentelectrode 22 is a strip-shaped electrode formed of a transparentconductive material such as ITO and extends in the directionintersecting the common electrode 14 (that is, in the Y-direction in thefigure). As shown in FIG. 1, the surface of the first substrate 10provided with the common electrodes 14 thereon and the surface of thesecond substrate 20 provided with the segment electrodes 22 thereon arecovered with alignment films 15 and 23, respectively. The alignmentfilms 15 and 23 are each an organic film formed, for example, of apolyimide resin and are processed by rubbing treatment for determiningthe orientation of the liquid crystal 31 when a voltage is not appliedthereto.

The liquid crystal 31 held between the first substrate 10 and the secondsubstrate 20 changes its orientation direction in accordance with avoltage applied between the common electrode 14 and the segmentelectrode 22. Hereinafter, in this embodiment, as shown in a lower rightportion in FIG. 2, a region 5 at which the common electrode 14 and thesegment electrode 22 oppose each other is referred to as “dot”. That is,the dot 5 is a minimum unit of a region in which the orientationdirection of the liquid crystal 31 is changed in accordance with avoltage applied thereto. As shown in FIG. 2, a plurality of the dots 5is disposed in the X direction and the Y direction to form a matrix, andeach of the dots corresponds to one of red color (R), green color (G),and blue color (B). In addition, one set of three dots (subpixel) 5R,5G, and 5B corresponding to these three colors mentioned above forms onepixel(subpixel) which is a minimum unit of a display image.

Next, as shown in FIG. 1, on the internal surface (the liquid crystal 31side) of the first substrate 10, a shading layer 11, color filters 12,and an overcoat layer 13 are formed. Among those mentioned above, theovercoat layer 13 is formed of a resin material, such as an acrylic orepoxy resin, and serves to planarize steps formed by the shading layer11 and the color filters 12. The common electrodes 14 described aboveare formed on the surface of this overcoat layer 13.

The shading layer 11 has a grating shape so as to cover gaps (that is,regions other than those at which the common electrodes 14 and thesegment electrodes 22 oppose each other) formed between the dots 5disposed in a matrix and serves to shade the peripheries of the dots 5.This shading layer 11 is formed, for example, of a black resin materialcontaining carbon black or the like dispersed therein or a metal such aschromium (Cr).

Next, the color filters 12 (12R, 12G, and 12B) are formed of resinlayers so as to correspond to the dots 5 and are colored by dyes orpigments corresponding to the colors of the dots 5, that is, are eachcolored in one of red (R), green (G), and blue (B). Accordingly, oflight passing through the liquid crystal 31 and entering the firstsubstrate 10, light having a wavelength corresponding to the color ofeach color filter 12 is selectively emitted to the observation side. Inaddition, as shown in FIG. 1, in the color filters 12, opening portions121 are formed at positions each corresponding to an approximatelycentral portion of each dot 5, and these openings 121 will be describedlater. In this embodiment, the structure (so-called stripe pattern) isshown by way of example in which the color filters 12 having the samecolor are aligned along a plurality of the dots 5 disposed in the Ydirection.

FIG. 3 is a graph showing the transmittance properties of the colorfilters 12 used in this embodiment. In FIG. 3, the transverse axisrepresents the wavelength of light incident on the color filters 12, andthe vertical axis represents the transmittance (ratio of amount ofemitted light to that of incident light). As shown in the figure, thecolor filter 12R has a high transmittance for light having a wavelengthof approximately 600 nm or more corresponding to red color; the colorfilter 12G has a high transmittance for light having a wavelength ofapproximately 500 to 600 nm corresponding to green color; and the colorfilter 12B has a high transmittance for light having a wavelength ofapproximately 400 to 500 nm corresponding to blue color. In addition,when the maximum transmittances of the color filters 12 shown in FIG. 3are compared to each other, the maximum transmittance (approximately0.92) of the color filter 12R for red color is highest, and the maximumtransmittance (approximately 0.89) of the color filter 12B for bluecolor and the maximum transmittance (approximately 0.84) of the colorfilter 12G for green color are decreased in that order. That is, wheneach color filter 12 is irradiated with the same amount of light, theamount of light emitted from the color filter 12G for green color issmaller than those emitted from the color filter 12R for red color andthe color filter 12B for blue color.

In addition, as shown in FIGS. 1 and 2, a plurality of reflective layers21 is formed on the internal (the liquid crystal 31 side) surface of thesecond substrate 20. Each reflective layer 21 is a layer for reflectinglight incident from the first substrate 10 side and is a thin filmhaving light reflection properties, which is formed, for example, of apure metal such as aluminum or silver or an alloy primarily composed ofthe metal mentioned above. The reflective layer 21 of this embodiment isformed of an alloy containing silver as a primary component, palladium(Pd), and copper (Cu). In addition, the internal surface of the secondsubstrate 20 is roughened to form light scattering structures(irregularities) on the surfaces of the reflective layers 21; however,they are omitted in the figure. In this embodiment, instead of thestructure having the irregularities on the surface of each reflectivelayer 21, a so-called front light-scattering method may be usedimparting light-scattering properties to the surface of the polarizer102 located at the observation side.

FIG. 4 is a view showing the positional relationship between thereflective layer 21 and the segment electrode 22 and shows across-section (that is, a cross-section perpendicular to the extendingdirection of the segment electrode 22) of the structure when viewed fromthe line B–B′ shown in FIG. 2. As shown in the figure, all around thecross-sectional periphery of the reflective layer 21, which is in thedirection perpendicular to the segment electrode 22, is covered with thesegment electrode 22. In more particular, as shown in FIG. 4, a firstlayer 221 forming a part of the segment electrode 22 is formed on theinternal surface of the second substrate 20, and the reflective layer 21is formed so as to cover a part of the first layer 221 in the widthdirection. In addition, a second layer 222 forming the segment electrode22 is formed so as to cover the reflective layer 21 from the surfacethereof parallel to the second substrate 20 to the peripheries (endsurfaces) of the reflective layer 21 in the width direction. Accordingto this structure, the segment electrode 22 and the reflective layer 21are electrically connected to each other. ITO forming the segmentelectrode 22 has a relatively high resistance, and in contrast, an APCalloy forming the reflective layer 21 has a low resistance. As a result,since the segment electrode 22 and the reflective layer 21 are incontact with each other as shown in FIG. 4, the wiring resistance can bereduced.

On the surface parallel to the surface of the second substrate 20, thereflective layers 21 are each provided so as to overlap a part of eachdot 5, as shown in FIG. 2. In addition, the entire periphery of eachreflective layer 21 is located inside the dot 5. In other words, thereflective layers 21 are each disposed in the corresponding dot 5 andare separated from each other to form a matrix pattern.

A region of the dot 5 which overlaps the reflective layer 21(hereinafter referred to as “reflective region51”) serves as a regionreflecting light incident from the first substrate 10 side forperforming reflective display. That is, when reflective display isperformed, outside light such as sunlight or interior illumination lightincident on the liquid crystal panel 1 from the observation side isplaced in a predetermined polarized state after passing through thepolarizer 102 and the retardation film 101 and then reaches thereflective layer 21 after passing through the first substrate 10, thecolor filter 12, the common electrode 14, the liquid crystal 31, and thesegment electrodes 22 in that order. Subsequently, the light isreflected from the surface of the reflective layer 21 and then retracesthe route through which it passed. In this step, in accordance with thedifference in voltage between the common electrode 14 and the segmentelectrode 22, the orientation of the liquid crystal 31 is changed, andhence the amount of a part of the reflective light reflected from thereflective region 51, which passes through the polarizer 102 and isviewed by the observer, can be controlled in each dot 5.

On the other hand, a region of the dot 5 other than the reflectiveregion 51, that is, a region (hereinafter referred to as “transmissiveregion”) 52 of the dot 5 other than the region covered with thereflective layer 21, serves as a region transmitting light therethrough,which light is incident from the backlight unit 4 on the secondsubstrate 20, for performing transmissive display. That is, whentransmissive display is performed by turning on the light source 41 ofthe backlight unit 4, light emitted from the backlight unit 4 is placedin a predetermined polarized state after passing through the polarizer202 and the retardation film 201. Subsequently, after passing throughthe second substrate 20, (the transmissive region 52), the segmentelectrode 22, the liquid crystal 31, the common electrode 14, the colorfilter 12, and the first substrate 10 in that order, the light isemitted to the observation side. In this transmissive display, inaccordance with the difference in voltage between the common electrode14 and the segment electrode 22, the orientation of the liquid crystal31 is changed, and hence the amount of a part of the light passingthrough the transmissive region 52, which passes through the polarizer102 and is viewed by the observer, can be controlled in each dot 5.

Next, referring to FIG. 5, detailed structures of the reflective layers21 and the color filters 12 will be described. In FIG. 5, the dots 5 forthree colors forming one pixel are only shown.

As described above, each dot 5 has the reflective region 51 whichcorresponds to the reflective layer and which reflects light incidentform the first substrate 10 side by the reflective layer 21 and thetransmissive region 52 which corresponds to a region other than thereflective layer 21 and which transmits light incident from the secondsubstrate 20 side to the first substrate 10 side. As shown in FIG. 5, ineach color filter 12, the opening portion 121 is provided in a region ofthe dot 5 corresponding to the reflective region 51. The opening portion121 is a portion in which the color filter 12 is not provided, and inthis opening portion 121, the transparent overcoat layer 13 covering thecolor filters 12 and the shading layer 11 is filled. In the structuredescribed above, in a reflective display mode, when a part of lightreflected from the surface of the reflective layer 21 passes through thecolor filter 12 (portion other than the opening portion 121), the amountof the light is decreased by the presence of this color filter 12;however, on the other hand, light, passing through the opening portion121 and then being emitted to the first substrate 10 side, only passesthrough the transparent overcoat layer 13, and hence the amount of thelight is not substantially decreased. Accordingly, for example, evenwhen the transmittance of the color filter 12 is increased in order tosecure the chroma in a transmissive display mode (that is, the amount ofpigment or dye dispersed in the color filter 12 is increased), theamount of light used for reflective display can be sufficiently secured,and hence bright display can be performed. As described above, accordingto this embodiment, both the brightness in a reflective display mode andthe chroma in a transmissive display mode can be obtained.

Next, in this embodiment, as shown in FIG. 5, the areas of the openingportions 121 formed in the color filters 12 having different colors aredifferent from each other. That is, the area of the opening portion 121provided in the green color filter 12G is larger than that of each ofthe red color filter 12R and the blue color filter 12B. As describedabove with reference to FIG. 3, the maximum transmittance of the greencolor filter 12G is lower than that of each of the red color filter 12Rand the blue color filter 12B. That is, the areas of the openingportions 121 of the individual color filters 12 are determined inaccordance with the difference in transmittance properties of the colorfilters 12.

In addition, as shown in FIGS. 2 and 5, the areal ratios of thereflective region 51 to the transmissive region 52 are different amongthe color filters 12 in accordance with the transmittance propertiesthereof. In other words, the areas of the reflective layers 21corresponding to the individual dots 5 are different from each other inaccordance with the colors therefor. In particular, the area of thereflective region 51 (or the reflective layer 21) corresponding to thegreen dot 5G is larger than that of each of the reflective regions 51(or the reflective layer 21) corresponding to the red and the blue dots5R and 5B.

As described above, when the areas of the opening portions 121 of thecolor filters 12 and the areas of the reflective layers 21 are madedifferent in accordance with the colors for the dots 5, the differencein transmittance properties among the individual color filters 12 can becompensated, and hence advantage can be obtained in that superiordisplay quality can be obtained. Hereinafter, this advantage describedabove will be described in detail.

First, the area of the opening portion 121 provided in each color filter12 will be described. Since the maximum transmittance of the green colorfilter 12G is low as compared to that of each of the filters 12 for theother colors, when the opening portions 121 of all the color filters 12are assumed to have the same area, the amount of light passing throughthe green color filter 12G is smaller than that of each of the red andthe blue color filters 12R and 12B. Accordingly, in a reflective displaymode, the amounts of light for individual colors, red, green, and blueviewed by the observer vary from each other, and as a result, it becomesdifficult to realize superior color reproducibility. On the other hand,in this embodiment, since the opening portion 121 having a large area isformed in the green color filter 12, which has a low transmittance, ascompared to the area of the opening portion 121 of each of the othercolor filters 12R and 12B, the amounts of light for individual colors,red, green, and blue viewed by the observer can be well balanced in areflective display mode.

Next, the area of the reflective layer 21 of each dot 5 will bedescribed. Since the maximum transmittance of the green color filter 12Gis low as compared to that of each of the filters 12 for the othercolors, when the reflective regions 51 of the dots for all colors areassumed to have the same area, the amount of light, which is reflectedfrom the surface of the reflective layer 21 corresponding to the greendot 5 and is then emitted to the observer side, is smaller than theamount of light which is reflected from the surface of the reflectivelayer 21 corresponding to each of the dots 5 for the other colors and isthen emitted to the observer side. Accordingly, the amounts of light forindividual colors viewed by the observer vary from each other. On theother hand, in this embodiment, since the reflective layer 21corresponding to the green dot 5G has a large area as compared to thatof each of the reflective layers 21 corresponding to the other dots 5Rand 5B, the amount of light, which is reflected from the surface of thereflective layer 21 corresponding to the green dot 5G and is thenemitted to the observer side, can be sufficiently secured.

As described above, according to this embodiment, even when thetransmittance properties of the color filters 12 for various colors varyfrom each other, the variation can be compensated, and hence superiorcolor reproducibility can be realized.

Referring again to FIG. 5, the positional relationship of the reflectiveregion 51 and the transmissive region 52 in the dot 5 will be described.In this embodiment, both the reflective region 51 and the transmissiveregion 52 are provided adjacent to a pair of sides, extending in the Ydirection, among four sides (that is, four sides forming the peripheryof the dot 5) defining the dot 5, and are adjacent to each other alongthe pair of sides described above. That is, along each of the two longsides of the dot 5 in an approximately rectangular shape from one end tothe other end thereof, the transmissive region 52, the reflective region51, and the transmissive region 52 are provided adjacent to each otherin that order. In other words, as shown in FIG. 5, when a linear line L,which is adjacent to the long side of the dot 5 and is parallel thereto,is assumed in the dot 5, the linear line L passes through both thereflective region 51 and the transmissive region 52.

As described above, in this embodiment, since the reflective region 51and the transmissive region 52, which correspond to one dot 5, areprovided adjacent to each other along the periphery of the dot 5,variation in areal ratio of the reflective region 51 to the transmissiveregion 52 in the dot 5, which is caused by manufacturing errors, can besuppressed. The details will be described below.

As the structure in which the reflective region 51 and the transmissiveregion 52 are formed in one dot 5, for example, the structure shown inFIG. 6( a) may also be considered. That is, the periphery of thereflective layer 21 corresponding to the dot 5 is formed so as not to beadjacent to the periphery of the dot 5, in other words, the reflectivelayer 21 is formed so that only the transmissive region 52 is formedadjacent to the periphery of the dot 5.

Next, among steps of manufacturing the liquid crystal panel 1 having thestructure described above, a step of bonding the second substrate 20 onwhich the reflective layers 21 are provided and the first substrate 10on which the shading layer 11 is formed to each other will be described.In this step, in general, the substrates described above are bonded toeach other while being relatively aligned. In this step, for example,assuming that the relative position between the two substrates in the Xdirection is misaligned by the reasons relating to manufacturingtechniques or the like, a part of the transmissive region 52 of the dot5 is covered with the shading layer 11, as shown in FIG. 6( b). Sincethe part of the transmissive region 52 covered with the shading layer 11as described above becomes unable to perform display, the area of thetransmissive region 52 in the dot 5 becomes small as compared to thecase in which the shading layer 11 is appropriately disposed (that is,the case shown in FIG. 6( a)). On the other hand, since the reflectiveregion 51 is not adjacent to the periphery of the dot 5, even when therelative position between the substrates is misaligned as describedabove, the reflective region 51 is not covered with the shading layer11. That is, the area of the reflective region 51 in the dot 5 is notchanged from that shown in FIG. 6( a). As described above, in thestructure shown in FIG. 6, due to the error caused by misalignmentbetween the substrates, since the area of the transmissive region 52 isdecreased and the area of the reflective region 51 is not changed, theareal ratio of the reflective region 51 to the transmissive region 52becomes different from that determined beforehand. As a result, thebrightness may vary in accordance with a display mode in some cases;hence, for example, the brightness in a transmissive display modebecomes dark as compared to that in a reflective display mode.

On the other hand, in this embodiment, the reflective region 51 and thetransmissive region 52 are formed in the vicinity of the plurality ofsides defining one dot 5 and are adjacent to each other along the sidesthereof. As a result, when the relative position between the firstsubstrate 10 and the second substrate 20 is misaligned in the Xdirection with respect to an appropriate position (a designed position)shown in FIG. 7( a), as shown in FIG. 7( b), in addition to the area ofthe transmissive region 52, the area of the reflective region 51 is alsodecreased. That is, according to this embodiment, even when the relativeposition between the reflective region 51 and the shading layer 11 ismisaligned, the case in which only one of the areas of the transmissiveregion 52 and the reflective region 51 is decreased can be avoided, andhence the change in areal ratio of the reflective region 51 to thetransmissive region 52 from a predetermined ratio can be suppressed.

Second Embodiment

Next, a liquid crystal panel according to a second embodiment of thepresent invention will be described.

In the first embodiment, the structure in which the shading layer 11,the color filters 12, and the overcoat layer 13 are provided on thefirst substrate 10 located at the observation side is described by wayof example. In this embodiment, the structure in which the elementsdescribed above are provided on the second substrate 20 is formed.

FIG. 8 is a cross-sectional view showing the structure of the liquidcrystal panel of this embodiment, and FIG. 9 includes a plan view and across-sectional view showing the positional relationship between dots,color filters and reflective layers in the liquid crystal panel. Thesame reference numerals of the constituent elements of the liquidcrystal panel 1 according to the first embodiment designate theequivalent constituent elements shown in FIGS. 8 and 9.

As shown in FIGS. 8 and 9, on the second substrate 20, a plurality ofthe reflective layers 21 of the respective dot 5 are formed. Thesereflective layers 21 are equivalent to those described in the abovefirst embodiment. That is, the reflective layers 21 are each formedinside the periphery of the dot 5 as shown in FIG. 9; the shapes thereofare each determined so that the reflective region 51 and thetransmissive region 52 are adjacent to each other and are provided alongthe periphery of the corresponding dot 5; and the area of the reflectivelayer 21 corresponding to the green dot 5G is smaller than that of eachof the reflective layers 21 corresponding to the dots 5R and 5B for theother colors.

In addition, on the surface of the second substrate 20 on which theplurality of reflective layers 21 are formed, the shading layer 11overlapping the gaps formed between the dots 5 and the color filters 12(12R, 12G, and 12B) having colors corresponding to the individual dots 5are provided. As shown in FIG. 9, in each color filter 12, the openingportion 121 is formed in a region corresponding to the reflective region51. As in the above first embodiment, the areas of the opening portions121 for the dots 5 corresponding to different colors are different. Thatis, as shown in FIG. 9, the area of the opening portion 121corresponding to the green dot 5 is larger than that of each of openingportions 121 corresponding to the red and the blue dots 5R and 5B.

Furthermore, the surface of the second substrate 20 on which thereflective layers 21, the shading layer 11, and the color filters 12 areprovided is covered with the overcoat layer 13, and on the surface ofthis overcoat layer 13, the segment electrodes 22 are formed. Thesesegment electrodes 22 has the structure different from that shown inFIG. 4 (the structure composed of the first layer 221 and the secondlayer 222) and are each formed of a single layer of a transparentconductive material. The surface of the overcoat layer 13 on which thesegment electrodes 22 are provided is covered with the alignment film23.

On the other hand, as shown in FIG. 8, on the internal surface of thefirst substrate 10, the common electrodes 14 are formed, and thesecommon electrodes 14 are covered with the alignment film 15. In thecross-sectional view shown in FIG. 9, the individual elements on thefirst substrate 10 are omitted.

By the structure in which the shading layer 11, and the color filters 12are provided on the second substrate 20 as described above, the sameadvantages as described in the above firs embodiment can also beobtained. That is, as described in the first and the second embodiments,regardless of whether the color filters 12 are provided on the firstsubstrate 10 located at the observation side or the second substrate 20located at the rear surface side, the present invention can be applied.However, since the shading layer 11 or the color filters 12 aregenerally formed with relatively high accuracy using photolithographictechnique, etching technique, and the like, the case in which therelative position between the reflective layers 21 and the shading layer11 is misaligned may be unlikely to occur as compared to the case inwhich the shading layer 11 is formed on the first substrate 10. Inconsideration of this situation, the advantage in which the error inareal ratio of the reflective region 51 to the transmissive region 52can be suppressed, which is described with reference to FIGS. 6 and 7,is particularly significant when the shading layer 11 (and the colorfilters 12) is formed on the first substrate 10.

Modified Embodiments

Heretofore, the first and the second embodiments have been described;however, the above embodiments are described by way of example, andvarious modifications may be performed without departing from the spiritand the scope of the present invention. As modified embodiments, thefollowing embodiments will be described by way of example.

First Modified Embodiment

In the first and the second embodiments described above, in order tocompensate for the difference in transmittance properties among thecolor filters 12 corresponding to different colors, the areas of thereflective layer 21 and the opening portion 121 of the color filter 12Gcorresponding to the green dot 5G are made different from thosecorresponding to the red dot 5R and blue dot 5B, and, in addition, theareas of those described above corresponding to the red dot, green dot,and blue dot may be made different from each other. In addition, in theembodiments described above, the areas of the reflective layers 21 andthe areas of the opening portions 121 of the color filters 12corresponding to the individual color dots are made different from eachother in accordance with the transmittance properties of the colorfilters 12, and in addition, the areas described above corresponding tothe individual color dots may be made different from each other inaccordance with the spectral properties of light emitted from thebacklight unit. That is, for example, when the spectral properties oflight emitted from the backlight unit 4 vary such that the amount oflight having a wavelength corresponding to blue is smaller than each ofthe amounts of light having wavelengths corresponding to green an red,the transmissive region 52 of the dot 5B having a large area may besecured by decreasing the area of the reflective layer 21 correspondingto the blue dot 5B so that the area described above is made smaller thanthat of each of those corresponding to the dots 5 for the other colors.As described above, the parameters for determining the area of thereflective layer 21 and the area of the opening portion 121 of the colorfilter 12 corresponding to each dot 5 are not limited to thetransmittance properties of the color filters 12. In addition, in thepresent invention, it is not always necessary that the area of thereflective layer 21 and the area of the opening portion 121 of the colorfilter 12 in each dot 5 be changed.

Second Modified Embodiment

In the above first embodiment, as shown in FIG. 4, the structure inwhich the reflective layer 21 is in contact with the segment electrode22 is described by way of example; however, they are not alwaysnecessary to be in contact with each other. That is, as shown in FIG.10, the structure may be formed in which the surface of the secondsubstrate 20 on which the reflective layers 21 are provided is coveredwith an insulating layer 25 formed of a resin material or the like, andon the surface of this insulating layer 25, the segment electrodes 22composed of single-layered transparent conductive films are formed.

Third Modified Embodiment

In the first and the second embodiment described above, the passivematrix type liquid crystal panel having no switching elements isdescribed by way of example; however, as in the above embodiments, thepresent invention may be applied to an active matrix type liquid crystalpanel provided with two-terminal switching elements such as TFDs (ThinFilm Diodes) or three-terminal switching elements such as TFTs (ThinFilm Transistors). In addition, in the above embodiments, the stripepattern in which the color filters 12 having the same color are alignedin a row is described by way of example; however, as the patterns of thecolor filters 12, in addition to this stripe pattern, a mosaic patternor a delta pattern may also be used.

Third Embodiment

Next, a third embodiment will be described. A liquid crystal displaydevice of the third embodiment is an example of a passive matrix typetransflective color liquid crystal display device. FIG. 11 is aschematic cross-sectional view showing the structure of the liquidcrystal display device of the third embodiment, and FIG. 12 is anenlarged plan view of a plurality of pixels forming a display region.

As shown in FIG. 11, a liquid crystal display device 1001 of the thirdembodiment comprises a liquid crystal cell 1002 and a backlight unit1003 (lighting means). In the liquid crystal cell 1002, a lowersubstrate 1004 and an upper substrate 1005 are disposed so as to opposeeach other with a sealing material 1006 provided therebetween; a liquidcrystal layer 1007 composed of STN (Super Twisted Nematic) liquidcrystal or the like is enclosed in the space surrounded by the uppersubstrate 1005, the lower substrate 1004, and the sealing material 1006;and the backlight unit 1003 is disposed at the rear surface side (outersurface side of the lower substrate) of the liquid crystal cell 1002.

On the internal surface side of the lower substrate 1004 composed of alight transparent material such as glass or plastic, segment electrodes1010 having a two-layered structure are formed in a strip shapeextending in the direction penetrating the plane. Each of the segmentelectrodes comprises a reflective metal film 1008 having a highreflectance and containing aluminum, silver, an alloy thereof, or thelike, and a transparent conductive film 1009 formed of indium tin oxide(hereinafter referred to as “ITO”) or the like and provided on thereflective film 1008. On the segment electrodes 1010, an alignment film1011, which is composed, for example, of a polyimide resin and whosesurface is processed by rubbing treatment, is formed. In the structureof the segment electrode 1010 of this embodiment, the transparentconductive film 1009 is not only layered on the reflective film 1008,but also has a large pattern width than that of the reflective film 1008so as to cover the side surfaces of the reflective film 1008 in additionto the upper surface thereof.

On the internal surface side of the upper substrate 1005 composed of atransparent material such as glass or plastic, there are provided colorfilters 1015 which comprise color layers 1013R, 1013G, and 1013B havingred color (R), green color (G), and blue color (B), respectively, and ashading portion 1014 (black matrix) defining the color layers 1013R,1013G, and 1013B and having different color therefrom. The shadingportion 1014 is formed, for example, of a resin black or a metal, suchas chromium, having a relatively low reflectance. In addition, on thecolor filters 1015, there is provided an overcoat film 1016 whichplanarizes steps formed between the color layers 1013R, 1013G, and 1013Band which also protects the surfaces thereof. The overcoat film 1016 maybe a resin film such as an acrylic or a polyimide film or an inorganicfilm such as a silicon oxide film. Furthermore, on the overcoat film1016, there are provided single-layered common electrodes 1017 which areformed of ITO or the like in a strip shape and extend in the directionparallel to the plane. On the common electrodes 1017, an alignment film1018, which is composed of a polyimide resin or the like and whosesurface is processed by rubbing treatment, is formed.

On the outer surface of the lower substrate 1004, a retardation film1020 and a polarizer 1021 are provided in that order from the substrateside, and in addition, at the outer surface side of the polarizer 1021,the backlight 1003 is provided. The backlight 1003 has a light source1022 such as a cold cathode tube or a light-emitting diode (LED), areflective plate 1023, and a light guide 1024. In addition, on the outersurface of the upper substrate 1005, a retardation film 1025 and apolarizer 1026 are provided in that order from the substrate side.

The electrodes on the substrates 1004 and 1005 are disposed as shown inFIG. 12, and on the lower substrate 1004, a plurality of the segmentelectrodes 1010 is formed in a strip shape extending in the verticaldirection shown in FIG. 12. In addition, on the upper substrate 1005, aplurality of the common electrodes 1017 are formed in a strip shapeextending in the lateral direction shown in FIG. 12 so as toperpendicularly intersect the segment electrodes 1010. The color layers1013R, 1013G, and 1013B for R, G, and B, respectively, of the colorfilter 1015 are disposed along the extending segment electrodes 1010.That is, the color filters 1015 of this embodiment form a so-calledvertical stripe pattern, and the color layers 1013R, 1013G, and 1013Bfor R, Q and B, respectively, have a strip shape and extend in thevertical direction. Accordingly, three dots 1028R, 1028G, and 1028B forR, G, and B, respectively, disposed in the lateral direction as shown inFIG. 12 form one pixel 1029 constituting a display pattern. In thisembodiment, the dot is a part at which the segment electrode 1010 andthe common electrode 1017 intersect each other and is a minimum unit forperforming display.

In this embodiment, the reflective film 1008 and the transparentconductive film 1009 form the segment electrode 1010 having thetwo-layered structure, and of these two films, the reflective film 1008functions as a reflective film for performing display in a reflectivedisplay mode. The reflective film 1008 and the transparent conductivefilm 1009 both extend in the vertical direction and have the widthsdifferent from each other, and as described above, the pattern width ofthe transparent conductive film 1009 is larger than that of thereflective film 1008. As a result, in each dot 1028R, 1028G, and 1028B,the central portion is a region in which the reflective film 1008 andthe transparent conductive film 1009 are present, and this region is areflective region R used in a reflective display mode of a transflectiveliquid crystal display device. In addition, each side of the reflectiveregion R is a region in which only the transparent conductive film ispresent, and this region is a transmissive region T used in atransmissive display mode of a transflective liquid crystal device. Thatis, in each dot 1028R, 1028G, and 1028B, both the reflective region Rand the transmissive region T are present.

In addition, in this embodiment, the width of the reflective film 1008is not uniformly formed, and at the central portion of each of the dots1028R, 1028G, and 1028B, width expansion portion 1008 a is formed havinga larger width than that of the other parts of the film. In addition,the color layers 1013R, 1013G, and 1013B for R, G, and B of the colorfilter 1015 on the upper substrate 1005 are not provided in the entirearea of the respective dot 1028R, 1028G, and 1028B, and an openingportion (white portion shown in FIG. 12) is provided in each of thecolor layers 1013R, 1013G, and 1013B in the dot 1028R, 1028G, and 1028B,respectively. That is, these opening portions are non-color regions1031R, 1031G, and 1031B, and in particular, the non-color regions 1031R,1031G, and 1031B are each formed in a region overlapping the widthexpansion portion 1008 a of the reflective film 1008 in plan view so asto be placed within the width expansion portion 1008 a. That is, each ofthe non-color regions 1031R, 1031G, and 1031B is a region in which onlythe reflective film 1008 and the transparent conductive film 1009 arepresent; the reflective region R other than the non-color region is aregion in which the reflective film 1008, the transparent conductivefilm 1009, and one of the color layers 1013R, 1013G, and 1013B of thecolor filter are present; and the transmissive region T is a region inwhich the transparent conductive film 1009 and one of the color layers1013R, 1013G, and 1013B are present. In this embodiment, the widthexpansion portion 1008 a is in an approximately rectangular shape, andthe non-color regions 1031R, 1031G, and 1031B are each in anapproximately rectangular shape.

In the liquid crystal display device 1001 having the structure describedabove, in a reflective display mode, since a part of outside lightincident from the upper substrate 1005 side passes through the non-colorregions 1031R, 1031G, and 1031B in the reflective regions R, the lightpassing through the color filter 1015 twice in a reflective display modecomprises non-colored light passing through the non-color regions 1031R,1031G, and 1031B and colored light passing through the color regions. Onthe other hand, in a transmissive display mode, all the light emittedfrom the backlight 1003 and passing through the transmissive regions Tpasses through the color regions, hence all the light passing throughthe color filter 1015 once in a transmissive display mode is coloredlight. As described above, the difference in tint of color between lightpassing through the color filter 1015 twice in a reflective display modeand light passing through the color filter 1015 once in a transmissivedisplay mode can be reduced, and when the color layers 1013R, 1013G, and1013B of the color filter 1015 are optimized, display exhibiting finecolors in both a reflective and a transmissive display mode and havingsuperior visibility can be obtained.

In addition, in this embodiment, since the transparent conductive film1019 and the reflective film 1008 form the two-layered segment electrode1010, due to the presence of the transparent conductive film 1009located in the transmissive region T, application of an electric fieldto the liquid crystal layer 1007 above the transmissive region T can besmoothly performed, and in addition, due to the presence of thereflective film 1008 composed of a metal having a small resistivity ascompared to that of the transparent conductive film 1009, an effect inthat the resistance of the entire segment electrode 1010 is reduced canbe obtained.

When the liquid crystal display device having the structure according tothe first embodiment is formed using a general method, the areas of thenon-color regions are likely to vary, and misalignment between thereflective region and the no-color region is likely to occur. Thereasons for this will be described below.

First, as in this embodiment, it is assumed that the reflective filmforms a part of a strip-shaped electrode. In this case, as describedabove, it is preferable that the effects, for example, of reducing theresistance of the electrode can be obtained; however, it is naturallyunderstood that the reflective film must be patterned into a stripshape. Since the reflective region and the transmissive region areformed in one dot in the liquid crystal display device of the firstembodiment, for example, it may also be considered that, after areflective film is formed so as to cover the entire dot, a windowportion (transmissive region) for light transmission is formed in thereflective film. However, as described above, since the reflective filmdescribed above is also patterned after all into a strip shape, when thewidth of the metal film pattern is designed to be small as compared tothat of the transparent conductive film pattern, the both sides of themetal film automatically become the transmissive regions, and hencedesign can be easily performed compared to the case in which the windowportion is intentionally formed.

That is, according to the easiest pattern design, as shown in FIG. 23,the pattern width of a strip-shaped reflective film 1108 is made smallas compared to that of a strip-shaped transparent conductive film 1109forming a segment electrode 1110. In addition, since the non-colorregion is provided in the reflective region of the liquid crystaldisplay device according to the first embodiment, a non-color region1131 (opening portion in the color layer) in which the color layer ofthe color filter is not present is provided above the reflective film1108. As shown in FIG. 23, in color liquid crystal display devices,since a dot 1128 itself generally has a rectangular shape having thelonger side in the vertical direction, the shape of the reflectiveregion R also has a rectangular shape having the longer side in thevertical direction, and in addition, the non-color region 1131 also hasa rectangular shape having the longer side in the vertical direction.

As described above, when the liquid crystal display device of the firstembodiment is formed, the shape of the opening portion (non-colorregion) in the color layer naturally becomes a rectangular having thelong side in the vertical direction, and as the area of the openingportion is increased, a rectangular shape having a longer side in thevertical direction is formed. When a color layer having an opening inthis type of shape as described above is formed by a photolithographictechnique, when variation in dimension is generated by etching,variation in area of the opening portion is increased. The reason forthis is that, for example, in the case in which a square pattern and arectangular pattern having the same area as that thereof are compared toeach other, when the same etching error in dimension is generated forthe two patterns described above, the change in area of the rectangularpattern becomes larger than that of the square pattern and is alsoincreased as the rectangular pattern has a longer side. As a result,variation in display properties such as the brightness and hue in areflective display mode is increased. In addition, when the width of theopening portion is excessively decreased, and the dimension thereofexceeds the limit of the resolution of a photolithographic technique, aproblem may arise in that the opening portion cannot be formed at all.

In addition, for example, when the reflective film is formed on thelower substrate, and the color filter is formed on the upper substrate,in order to form the non-color region reliably in the reflective region,alignment accuracy between the pattern for the reflective film and thatfor the color filter, that is, alignment accuracy when the lowersubstrate is bonded to the upper substrate, becomes important. However,when a non-color region in a rectangular shape having an area to someextent is disposed in a reflective region having a rectangular shape,the distance between the end of the reflective region in the short sidedirection and the end of the non-color region in the short sidedirection is inevitably decreased, and as a result, the alignmentallowance is decreased. Hence, the case in which, depending on design,the distance between the end of the reflective region and the end of thenon-color region may be smaller than the misalignment in asubstrate-bonding step in some cases may be considered. In this case,when the non-color region protrudes into the transmissive region,desired optical properties cannot be obtained.

On the other hand, in the liquid crystal display device of thisembodiment as shown in FIG. 12, the width expansion portion 1008 a ofthe reflective film 1008 is provided in each of the dots 1028R, 1028G,and 1028B, and in addition, the non-color regions 1031R, 1031G, and1031B are each disposed to overlap the width expansion portion 1008 a inplan view. Accordingly, the reflective region R in which each of thenon-color regions 1031R, 1031G, and 1031B is disposed has a shape closeto a square shape as compared to that of a conventional reflectiveregion. Hence, when a predetermined variation in etching dimensionoccurs, variation in area of the opening portion can be decreased ascompared to that in the past, and variation in display properties in areflective display mode can be decreased. In addition, when thereflective region R, in which each of the non-color regions 1031R,1031G, and 1031B is disposed, has a shape close to a square shape ascompared to that in the past, since the distance G between the end ofthe reflective region R and each end of the non-color regions 1031R,1031G, and 1031B can be larger than that in the past, the alignmentallowance is increased, and hence, in addition to the structure havingresistance against bonding misalignment, desired optical properties canalso be obtained.

Fourth Embodiment

Hereinafter, a fourth embodiment of the present invention will bedescribed with reference to drawings.

FIG. 13 is an enlarged plan view of a plurality of pixels forming adisplay region of a liquid crystal display device of the fourthembodiment, and corresponds to the views shown in FIG. 12 of the thirdembodiment. The basic structure of the liquid crystal display device ofthis embodiment is equivalent to that of the third embodiment, and theshapes of a reflective region and a non-color region are only differentfrom those of the third embodiment. The same reference numerals of theconstituent elements in FIG. 12 designate the same constituent elementsin FIG. 13, and descriptions thereof are omitted.

In the third embodiment, in each of dots corresponding to colors R, G,and B different from each other, the area and shape of the reflectiveregion and the area and the shape of the no-color region are equivalentto each other; however, in this embodiment, among dots corresponding tocolors R, G and B different from each other, the area of at least onereflective region and the area of at least one non-color region aredifferent from the others, and accordingly, the shape of the reflectiveregion and the shape of the non-color region are different from theothers.

In particular, as shown in FIG. 13, among the dots 1028R, 1028G, and1028B having different colors from each other, the area of thereflective region R in the dot 1028G for G is largest, and the areas ofthe reflective region R in the dot 1028B for B and the reflective regionR in the dot 1028R for R becomes smaller in that order. In other words,the area of the transmissive region T in the dot 1028G for G issmallest, and the areas of the transmissive region T in the dot 1028Bfor B and the transmissive region T in the dot 1028R for R becomeslarger in that order. In addition, the area of the non-color region1031G in the dot 1028G for G is largest, and the areas of the non-colorregion 1031R in the dot 1028R for R and the non-color region 1031B inthe dot 1028B for B becomes smaller in that order.

According to the liquid crystal display device of this embodiment, sincethe reflectances, chromas in a reflective display mode, transmittances,and chromas in a transmissive display mode can be adjusted forindividual colors R, q and B, the brightness and color (for example, huein white display) of display in a reflective display mode and thebrightness and color (for example, hue in white display) of display in atransmissive display mode can be optionally adjusted. Accordingly, thedisplay qualities both in a reflective display mode and in atransmissive display mode can be equally optimized.

In more particular, the area of the transmissive region T of the dot1028G for G is set to smaller than that of each of the transmissiveregions T of the dots 1028R for R and 1028B for B. Since green light hasa sufficiently high spectral luminous factor as compared to that of eachof red color and blue color, although the areas are set as describedabove, the color balance is not degraded, and in addition, a sufficienttransmittance can also be maintained. Furthermore, since the area of thenon-color region 1031G of the dot 1028G for G is set to larger than thatof each of the non-color regions 1031R and 1031B of the dots 1028R for Rand 1028B for B, respectively, the reflectance and color reproducibilityin a reflective display mode can be improved.

In the third and fourth embodiments described above, the width expansionportion of the reflective film having an approximately rectangular shapeand the non-color region having an approximately rectangular shape aredescribed by way of example; however, the shapes thereof are notspecifically limited to a rectangular shape. For example, as shown inFIG. 14, the shape of a width expansion portion 1008 b may be anapproximately hexagon, and accordingly the shape of a non-color region1031 b may also be an approximately hexagon, or as shown in FIG. 15, theshape of a width expansion portion 1008 c may be an approximately oval,and accordingly the shape of a non-color region 1031 c may also be anapproximately oval.

In addition, in the embodiments described above, the structure in whichthe transparent conductive film is provided on the reflective film toform a two-layered electrode is described by way of example; however, itis not always necessary for a metal film functioning as a reflectivefilm in the present invention to form the electrode, and an insulatingfilm may be provided between the metal film and the transparentconductive film so that the metal film functions exclusively as areflective film. However, in this case, in the present invention, themetal film must be formed into a strip shape. In addition, in theembodiments described above, the vertical stripe pattern is described asa pattern of the color filters by way of example, and in addition tothat, the present invention may also be applied to color filtersdisposed in a transverse stripe pattern, a mosaic pattern, a deltapattern, or the like. Furthermore, in addition to a passive matrix typeliquid crystal display device described in the above embodiments by wayof example, the present invention may be applied to an active matrixtype liquid crystal display device using TFDs as a switching element.

EXAMPLES

Next, by the inventors of the present invention, simulation of opticalproperties, such as reflectances, transmittance, and display colors,were performed by changing various parameters using the liquid crystaldisplay device of the present invention, and as a result, the advantagesof the present invention were verified. Hereinafter, the results will bedescribed.

As the basic conditions of the simulation, the number of dots was set to120×3 (R, G and B) rows×160 columns, a dot pitch in the transversedirection was set to 85 μm, and a dot pitch in the vertical directionwas set to 255 μm. FIGS. 16 to 19 are views showing dimensions ofindividual parts of a dot G according to structural examples 1 to 3described below, and FIG. 20 is a view showing dimensions of individualparts in a pixel of structural example 3 described below. In thesefigures, a region (meshed region) indicated by the arrow B is a blackmatrix between dots, and the widths of the black matrix extending in thetransverse direction and in the vertical direction were set to 13 and 9μm, respectively. As a result, a dot pitch area (area of a dot includingthe black matrix) was set to 21,675 μm², and a dot area (area of a dotexcluding the black matrix) was set to 18,392 μm². In addition, a colorfilter having the spectral properties shown in FIG. 21 was used.

Structural Example 1

In structural example 1, the transmissive regions of dots R, G and Bwere each formed to have a uniform region of 8,712 μm². In addition, theareas of the non-color regions in the dots R and B were each set to 360μm², and the non-color region in the dot G was formed to have a largearea of 2,161 μm². The reflectance, the area of color region and thewhite display color in a reflective display mode, the transmittance, andthe white display color and the area (area of a triangle formed by threecoordinates of red, green, and blue color display in an x-y coordinatesystem showing chromas) of color region in a transmissive display modewere calculated by simulation. In this example, both the area of colorregion and the white display color were values based on an xyY colorsystem chromaticity diagram. The optical properties described above areshown in Table 1 below.

Structural Example 2

In structural example 2, in a manner different from that in structuralexample 1, the areas of the transmissive regions of the individual dotswere changed therebetween. That is, the transmissive region of the dot Ghad a smallest area of 6,776 μm², and the areas of the transmissiveregions of dot B and dot R were increased in that order so as to be10,406 and 11,130 μm², respectively. In addition, concerning thenon-color region of each dot, the areas for the dot R and the dot G wereset to 180 and 3,240 μm, respectively. In addition, the non-color regionwas not provided in the dot B. The reflectance, the white display colorand the area of color region in a reflective display mode, thetransmittance, and the white display color and the area of color regionin a transmissive display mode were calculated by simulation. Theoptical properties described above are shown in Table 1 below.

Structural Example 3

In structural example 3, instead of the color filter having the spectralproperties shown in FIG. 21, a color filter having the spectralproperties shown in FIG. 22 was used. When the spectral properties shownin FIGS. 21 and 22 are compared to each other, the peak portions(transmissive regions) of the curves for the individual colors aresubstantially equivalent to each other; however, the transmittance levelin regions (absorption regions) other than the peaks in FIG. 21 ishigher than that in FIG. 22. In other words, in structural example 3, acolor filter having high color purity as compared to that in structuralexample 2 was used. In accordance with this change of the color filter,the areas of the transmissive region and the areas of the non-colorregion for the individual dots were slightly changed. The reflectance,the white display color and the area of color region in a reflectivedisplay mode, the transmittance, and the white display color and thearea of color region in a transmissive display mode were calculated bysimulation. The optical properties described above are shown in Table 1below.

The optical properties of the structural examples are as shown in Table1, and when a conventional linear and strip-shaped reflective region isused, pattern dimensions of the reflective region and the non-colorregion for realizing the areas of the individual portions of structuralexample 1 are, for example, as shown in FIG. 16. In FIGS. 16 to 20 shownbelow, the dimensions are represented by μm. In addition, when the areasof the individual portions of structural example 1, that is, when theareas of the individual portions as shown in FIG. 16 are realized by thestructure of the present invention in which the reflective region hasthe width expansion portion, the dimensions are, for example, as shownin FIG. 17.

In this case, the distance between the end of the reflective region andthe end of the non-color region extending in the vertical direction is15 μm in the structure shown in FIG. 16. In a process for manufacturinga liquid crystal display device, since a current level of misalignmentin a step of bonding the upper substrate to the lower substrate isapproximately 15 μm, when it is assumed that the maximum misalignmentbetween the upper and the lower substrates occurs, the alignmentallowance (margin) cannot be secured at all. On the other hand, in thestructure shown in FIG. 17, the distance between the end of thereflective region and the end of the non-color region is 18.7 μm.Accordingly, in this case, even when it is assumed that the maximummisalignment between the substrates occurs in a substrate-bonding step,a margin of approximately 3.7 μm can still be secured. As describedabove, according to the structure of the present invention, it isverified that the structure having resistance against bondingmisalignment can be formed.

Next, the lateral dimension of the non-color region will be described,the dimensions thereof shown in FIGS. 16 and 17 are 10 and 18.6 μm,respectively. For example, when it is assumed that the resolution of aphotolithographic technique used for manufacturing of a liquid crystaldisplay device is approximately 10 μm, the dimension shown in FIG. 16 isthe lowest value at which the opening portion can be formed, and in somecases, the opening portion may not be formed at all. On the other hand,according to the structure shown in FIG. 17, the non-color region can bereliably formed with superior accuracy.

Concerning the optical properties of structural example 1 shown in Table1, according to “white display color in a transmissive display mode”,x=0.314 and y=0.347 are satisfied; hence, it is indicated that slightlyyellowish white color is displayed. Accordingly, in order to furtherimprove the degree of whiteness of the white display color in atransmissive display mode, the areas of the individual parts wereadjusted, thereby forming the structure according to structural example2. In particular in this example, the area of the transmissive regionfor G in structural example 1 was significantly decreased, and in orderto maintain the transmittance equivalent to that in structural example1, the areas of the transmissive regions for R and B were bothincreased. In addition, on the other hand, since the area of thereflective region for G was increased, the area of the non-color regionfor G in structural example 1 was increased so that a G component inreflected light was decreased. In accordance with these changes, theareas of the non-color regions for R and B were adjusted so as tomaintain the reflectance and the color when reflected.

When the areas of the individual parts in structural example 2 arerealized by the structure of the present invention, in which the widthexpansion portion is present in the reflective region, for example, thestructure as shown in FIG. 18 is formed. In this structure, the distancebetween the end of the reflective region and the end of the non-colorregion was 18 μm, and hence the structure having resistance againstbonding misalignment could be formed. In addition, a non-color regionhaving a lateral dimension of 20 μm could be formed, and hencepatterning of the non-color region can be performed without anyproblems.

Next, in structural example 3, since a color filter having high colorpurity as compared to that in structural example 2 was used, that is,since a color filter having dark colors was used, the transmittanceequivalent to that in structural examples 1 and 2 cannot be maintainedunless the area of the transmissive region is increased. Accordingly,the areas of the transmissive regions of all the dots for R, G, and B instructural example 3 were increased from those in structural example 2,thereby forming the structure according to structural example 3. On theother hand, since the areas of the reflective regions of all the dotswere decreased, in order to maintain the reflectance, the areas of thenon-color regions of all the dots in structural example 2 wereincreased. As a result, although the reflectance and the area of colorregion in reflection were slightly decreased, in a reflective displaymode, optical properties approximately equivalent to those in structuralexamples 1 and 2 could be obtained. In a transmissive display mode, atransmittance of 4.5% equivalent to that in structural examples 1 and 2could be maintained, and in addition, the area of color region intransmittion could be increased to 3.6×10⁻²; hence, by using the colorfilter having high color purity, display color in a transmissive playmode could be made clearer.

The pattern dimensions for the reflective region and the non-colorregion to realize the areas of the individual parts in structuralexample 3 are, for example, as shown in FIG. 19 when a conventional,linear, strip-shaped reflective region is used. In addition, when theareas of the individual parts in structural example 3, that is, theareas of the individual parts equivalent to those shown in FIG. 19, arerealized by the structure of the present invention in which thereflective region has a width expansion part, for example, the structureas shown in FIG. 20 is obtained. In FIG. 20 showing structural example 3in which most preferable optical properties can be obtained among thestructural examples described above, the pattern dimensions for all thedots for R, G, and B are shown.

Concerning the distance between the end of the reflective region and theend of the non-color region extending in the vertical direction, in thestructure shown in FIG. 19, the distances in the lateral direction andin the vertical direction are 13.7 and 14.14 μm, respectively. When itis assumed that the misalignment in a step of bonding the uppersubstrate to the lower substrate is 15 μm, no alignment allowance can beobtained, and in addition, the non-color region may protrude outsidefrom the reflective region. As a result, desired optical properties maynot be obtained at all in some cases. On the other hand, in thestructure shown in FIG. 20, the distances in the dot G in the lateraland the vertical directions are 15.5 and 15.2 μm, respectively. When theareas of the individual parts in structural example 3 are realized, themargin is inevitably decreased even when the structure of the presentinvention is used; however, compared to the structure shown in FIG. 19,the margin is relatively large, and the structure having resistanceagainst bonding misalignment can be formed.

As can be seen from the results of the simulation described above,according to the structures of the present invention, the structurehaving resistance against bonding misalignment can be formed inmanufacturing a liquid crystal display device. In addition, it isverified that, by optimizing the areas of the transmissive region(reflective region) and the non-color region of each dot, a liquidcrystal display device can be realized in which superior display qualitycan be equally performed in both a reflective display mode and in atransmissive display mode.

Fifth Embodiment

Next, an embodiment of electronic apparatuses using a liquid crystaldisplay device (liquid crystal panel) of the present invention will bedescribed.

Mobile Computer

First, an example in which the liquid crystal display device (liquidcrystal panel) of the present invention is applied to a display portionof a mobile computer (so-called notebook type computer) will bedescribed. FIG. 24 is a perspective view showing the structure of thispersonal computer. As shown in the figure, a personal computer 91comprises a main body 912 provided with a keyboard 911 and a displayportion 913 to which the liquid crystal display device (liquid crystalpanel) according to one of the first to the fourth embodiments of thepresent invention is applied.

Mobile Phone

Next, an example in which the liquid crystal display device (liquidcrystal panel) of the present invention is applied to a display portionof a mobile phone will be described. FIG. 25 is a perspective viewshowing the structure of this mobile phone. As shown in the figure, inaddition to a plurality of operation buttons 921, a mobile phone 92comprises an earpiece 922, a mouthpiece 923, and a display portion 924to which the liquid crystal display device (liquid crystal panel)according to one of the first to the fourth embodiments of the presentinvention is applied.

As electronic apparatuses to which the liquid crystal display device(liquid crystal panel) of the present invention can be applied, inaddition to the personal computer shown in FIG. 24 and the mobile phoneshown in FIG. 25, for example, there may be mentioned liquid crystaltelevisions, view finder type or direct viewing type video taperecorders, car navigation apparatuses, pagers, electronic notebooks,electronic calculators, word processors, work stations, televisionphones, POS terminals, and digital still cameras. According to theliquid crystal display device (liquid crystal panel) of the presentinvention, the brightness both in a reflective display mode and thechroma in a transmissive display mode can be maintained, and hencesuperior display quality can also be maintained in both display systems.Accordingly, the liquid crystal display device of the present inventioncan be preferably used for electronic apparatuses in which superiordisplay quality are required in both reflective and transmissive displaymodes.

As has thus been described, according to the present invention, thebrightness both in a reflective display mode and the chroma in atransmissive display mode can be secured. Hence, a transflective colorliquid crystal display device which exhibits fine color in both areflective and a transmissive display mode and has superior visibilitycan be realized. In addition, the structure having resistance againstbonding misalignment can be realized in manufacturing process of aliquid crystal display device, and simultaneously, desired opticalproperties such as reflectance, transmittance, and hue of display colorcan be stably obtained.

The disclosures of Japanese Patent Application Nos. 2001-378701 and2002-061049 are incorporated by reference in their entirety.

TABLE 1 STRUCTURAL STRUCTURAL STRUCTURAL UNIT EXAMPLE 1 EXAMPLE 2EXAMPLE 3 DOT PITCH AREA μm² 21675 21675 21675 DOT AREA μm² 18392 1839218392 AREA OF RED μm² 8712 11130 11372 TRANSMISSIVE GREEN μm² 8712 67767260 REGION PER DOT BLUE μm² 8712 10406 10889 AREA OF RED μm² 360 180450 NON-COLOR GREEN μm² 2161 3240 3975 REGION PER DOT BLUE μm² 360 0 413REFLECTANCE % 20.0 20.3 19.4 AREA OF COLOR REGION IN ×10⁻² 2.1 2.2 2.0REFLECTION WHITE DISPLAY x — 0.328 0.324 0.327 COLOR IN y — 0.844 0.3570.351 REFLECTION TRANSMITTANCE % 4.5 4.5 4.5 AREA OF COLOR REGION IN×10⁻² 3.1 3.1 3.6 TRANSMISSION WHITE DISPLAY x — 0.314 0.316 0.313 COLORIN y — 0.347 0.327 0.325 TRANSMISSION

1. A liquid crystal display device comprising: dots corresponding todifferent color layers; a first substrate and a second substrateopposing to each other and holding a liquid crystal therebetween;reflective films provided over the first substrate and peripheral edgesof the reflective films disposed in the dots; and the color layers areprovided over the second substrate; wherein each of the color layers hasan opening portion overlapping each of the reflective films.
 2. A liquidcrystal display device comprising: a first substrate and a secondsubstrate opposing to each other and holding a liquid crystaltherebetween; a plurality of dots corresponding to different colorlayers; and reflective films provided over the second substrate andperipheral edges of the reflective films disposed in the dots; whereinthe color layers are provided over the first substrate and overlap thedots; each of the color layers has an opening portion overlapping one ofthe reflective films.
 3. An electronic apparatus comprising a liquidcrystal display device according to claim
 2. 4. A liquid crystal displaydevice comprising: a first substrate and a second substrate facing eachother; a liquid crystal layer provided between the first substrate andthe second substrate; a plurality of dots corresponding to a pluralityof different color layers; reflective films provided over the secondsubstrate and peripheral edges of the reflective films disposed in thedots; and the plurality of color layers having different colors anddisposed corresponding to the dots, the color layers provided over thefirst substrate; wherein the dots have reflective regions in which thereflective films are disposed and transmissive regions in which thereflective films are not disposed; and wherein the color layers havenon-color regions in which the color layers are not disposed, thenon-color regions overlap a part of each of the reflective regionswithin one of the dots as viewed in plan.
 5. A liquid crystal displaydevice according to claim 4, wherein at least one of the non-colorregions corresponding to at least one of the color layers has an areadifferent from an area of each of the non-color regions corresponding tothe other color layers.
 6. A liquid crystal display device according toclaim 4, wherein the color layers are composed of red layers, greenlayers and blue layers, the non-color regions corresponding to redlayers, green layers, and blue layers, and each of the non-color regionscorresponding to the green layers is larger than each of the non-colorregions corresponding to the red layers and the blue layers.
 7. A liquidcrystal display device according to claim 4, wherein each of thetransmissive regions corresponding to at least one of the color layershas an area different from an area of each of the transmissive regionscorresponding to the other color layers.
 8. A liquid crystal displaydevice according to claim 4, wherein the color layers are composed ofred layers, green layers, and blue layers, and each of the transmissiveregions corresponding to the green layers is smaller than each of thetransmissive regions corresponding to the red layers and the bluelayers.
 9. An electronic apparatus comprising the liquid crystal displaydevice according to claim 4.